Abstract: A method and apparatus for optimizing register allocation during scheduling and execution of program code in a hardware environment. The program code can be compiled to optimize execution given predetermined hardware constraints. The hardware constraints can include the number of register read and write operations that can be performed in a given processor pass. The optimizer can initially schedule the program using virtual registers and a goal of minimizing the amount of active registers at any time. The optimizer reschedules the program to assign the virtual registers to actual physical registers in a manner that minimizes the number of processor passes used to execute the program.

Abstract: A list scheduler in a compiler can select from a plurality of alternative instruction sequences for one or more computation performed within an application. A scheduler can initially identify and track one or more computations for which multiple alternative instruction sequences exist. An available instruction list can be populated with the alternative instruction sequences. The list scheduler can access the available instruction list during scheduling of the application. The list scheduler can perform a cost analysis while scheduling the instructions by performing a look ahead. The list scheduler may select alternate instruction sequences for similar computations occurring in different portions of the application based on the cost benefit analysis.